Daniel Cornfeld MD, Presenter: Stockholder, General Electric Company

Gary Michael Israel MD, Abstract Co-Author: Nothing to Disclose

Jeffrey C. Weinreb MD, Abstract Co-Author: Consultant, General Electric Company Speakers Bureau, General Electric Company Consultant, Bayer AG (Bayer Schering Pharma AG) Speakers Bureau, Bayer AG (Bayer Schering Pharma AG) Consultant, Tyco Healthcare (Mallinckrodt Inc)

Shirley M. McCarthy MD, PhD, Abstract Co-Author: Nothing to Disclose

Uterine myomas are common. Statistically, an unusual uterine mass is more likely to represent an atypical fibroid than a rare uterine neoplasm such as combined endometrial stromal and smooth muscle tumor, smooth muscle tumor of uncertain malignant potential (STUMP), endometrial stromal sarcoma (ESS), or leiomyosarcoma. One study [JMRI 20: 998-1007(2004)] retrospectively studied the MRI appearance of uterine tumors and concluded that three findings suggested a diagnosis other than fibroid: more than 50% high signal on T2WI, high-signal areas on T1WI, and well defined pockets of non-enhanecement. The purpose of this study was to test these criteria on our patient population.

Four patients with uterine leiomyosarcoma, two with STUMP, one with endometrial stromal sarcoma, and two with mixed endometrial stromal and smooth muscle tumors were included in the study. Seventeen additional cases of leiomyomas and their common variants plus one case of adenomyotic cyst were included as controls. Control cases were chosen by searching our report database for cases of uterine masses suspicous for either atypical myoma or neoplasm. Cases were blindly and independently evaluated by two experienced readers for the above three criteria and also for additional features that we believed to be useful for identifying rare uterine neoplasms. The additional features included enhancing areas of moderate T2 signal and well defined cystic spaces. All cases had pathologic correlation.

We found 33% sensitity and 70% specificity for the three tested criteria; values lower than in the literature. Additionally, 6 of 6 rare uterine neoplasms had areas that were bright on both T2W and post contrast images. Six of 10 myomas shared these characterisitics (11 patients did not receive IV contrast). Three of 9 rare uterine neoplasms had cystic spaces. Eight of 11 masses with cysts were myomas.

The hypothesized critera were neither sensitive nor specific for detecting rare uterine neoplasms.

Solid, moderately T2 bright tissue in a uterine mass should raise suspicion for a rare uterine neoplasm. Cystic spaces are more commonly associated with atypical myomas than with other uterine tumors.

Cornfeld, D, Israel, G, Weinreb, J, McCarthy, S, MR Imaging Findings of Uterine Stromal Neoplasms.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5005500.html